Also create parents when creating union/linkfiles source directories.
[live-boot-grml.git] / scripts / live-helpers
index 795de55..13a8cec 100644 (file)
@@ -519,8 +519,9 @@ where_is_mounted ()
 }
 
 trim_path () {
-    # remove all unnecessary /:s in the path, including last
-    echo ${1} | sed 's|//|/|g' | sed 's|/$||'
+    # remove all unnecessary /:s in the path, including last one (except
+    # if path is just "/")
+    echo ${1} | sed 's|//\+|/|g' | sed 's|^\(.*[^/]\)/$|\1|'
 }
 
 what_is_mounted_on ()
@@ -764,6 +765,22 @@ mount_persistent_media ()
        return 0
 }
 
+close_persistent_media () {
+       local device=${1}
+       local backing="$(where_is_mounted ${device})"
+
+       if [ -d "${backing}" ]
+       then
+               umount "${backing}" >/dev/null 2>&1
+               rmdir "${backing}" >/dev/null 2>&1
+       fi
+
+       if is_active_luks_mapping ${device}
+       then
+               /sbin/cryptsetup luksClose ${device}
+       fi
+}
+
 open_luks_device ()
 {
        dev="${1}"
@@ -832,15 +849,23 @@ probe_for_gpt_name ()
        local snapshots="${2}"
        local dev="${3}"
 
-       if ! is_gpt_device ${dev} || \
-          ( echo ${PERSISTENT_ENCRYPTION} | grep -qve "\<luks\>" && \
-            /sbin/cryptsetup isLuks ${dev} > /dev/null 2>&1 )
+       local gpt_dev="${dev}"
+       if is_active_luks_mapping ${dev}
+       then
+               # if $dev is an opened luks device, we need to check
+               # GPT stuff on the backing device
+               gpt_dev=$(get_luks_backing_device "${dev}")
+       fi
+
+       if ! is_gpt_device ${gpt_dev}
        then
                return
        fi
+
+       local gpt_name=$(get_gpt_name ${gpt_dev})
        for label in ${overlays} ${snapshots}
        do
-               if [ "$(get_gpt_name ${dev})" = "${label}" ]
+               if [ "${gpt_name}" = "${label}" ]
                then
                        echo "${label}=${dev}"
                fi
@@ -936,18 +961,16 @@ find_persistent_media ()
        do
                local result=""
 
-               local real_dev=""
                local luks_device=""
                # Check if it's a luks device; we'll have to open the device
                # in order to probe any filesystem it contains, like we do
-               # below. do_custom_mounts() also depends on that any luks
+               # below. activate_custom_mounts() also depends on that any luks
                # device already has been opened.
                if echo ${PERSISTENT_ENCRYPTION} | grep -qe "\<luks\>" && \
-                  /sbin/cryptsetup isLuks ${dev} >/dev/null 2>&1
+                  is_luks_partition ${dev}
                then
                        if luks_device=$(open_luks_device "${dev}")
                        then
-                               real_dev="${dev}"
                                dev="${luks_device}"
                        else
                                # skip $dev since we failed/chose not to open it
@@ -962,15 +985,7 @@ find_persistent_media ()
                # Probe for matching GPT partition names or filesystem labels
                if echo ${PERSISTENT_STORAGE} | grep -qe "\<filesystem\>"
                then
-                       local gpt_dev="${dev}"
-                       if [ -n "${luks_device}" ]
-                       then
-                               # When we probe GPT partitions we need to look
-                               # at the real device, not the virtual, opened
-                               # luks device
-                               gpt_dev="${real_dev}"
-                       fi
-                       result=$(probe_for_gpt_name "${overlays}" "${snapshots}" ${gpt_dev})
+                       result=$(probe_for_gpt_name "${overlays}" "${snapshots}" ${dev})
                        if [ -n "${result}" ]
                        then
                                ret="${ret} ${result}"
@@ -998,7 +1013,7 @@ find_persistent_media ()
 
                # Close luks device if it isn't used
                if [ -z "${result}" ] && [ -n "${luks_device}" ] && \
-                  /sbin/cryptsetup status "${luks_device}" 1> /dev/null 2>&1
+                  is_active_luks_mapping "${luks_device}"
                then
                        /sbin/cryptsetup luksClose "${luks_device}"
                fi
@@ -1028,17 +1043,22 @@ get_mac ()
        echo ${mac}
 }
 
-is_luks()
+is_luks_partition ()
 {
-    devname="${1}"
-    if [ -x /sbin/cryptsetup ]
-    then
-       /sbin/cryptsetup isLuks "${devname}" 2>/dev/null || ret=${?}
-       return ${ret}
-    else
-       return 1
-    fi
+       device="${1}"
+       /sbin/cryptsetup isLuks "${device}" 1>/dev/null 2>&1
+}
 
+is_active_luks_mapping ()
+{
+       device="${1}"
+       /sbin/cryptsetup status "${device}" 1>/dev/null 2>&1
+}
+
+get_luks_backing_device () {
+       device=${1}
+       cryptsetup status ${device} 2> /dev/null | \
+               awk '{if ($1 == "device:") print $2}'
 }
 
 removable_dev ()
@@ -1225,8 +1245,9 @@ get_custom_mounts ()
        # Side-effect: leaves $devices with live.persist mounted in ${rootmnt}/live/persistent
        # Side-effect: prints info to file $custom_mounts
 
-       local devices="${1}"
-       local custom_mounts="${2}" # print result to this file
+       local custom_mounts=${1}
+       shift
+       local devices=${@}
 
        local bindings="/tmp/bindings.list"
        local links="/tmp/links.list"
@@ -1240,7 +1261,6 @@ get_custom_mounts ()
                fi
 
                local device_name="$(basename ${device})"
-               local device_used=""
                local backing=$(mount_persistent_media ${device})
                if [ -z "${backing}" ]
                then
@@ -1250,12 +1270,6 @@ get_custom_mounts ()
                local include_list="${backing}/${persistence_list}"
                if [ ! -r "${include_list}" ]
                then
-                       umount "${backing}" >/dev/null 2>&1
-                       rmdir "${backing}" >/dev/null 2>&1
-                       if /sbin/cryptsetup status ${device_name} >/dev/null 2>&1
-                       then
-                               /sbin/cryptsetup luksClose "${device_name}"
-                       fi
                        continue
                fi
 
@@ -1264,39 +1278,32 @@ get_custom_mounts ()
                        cp ${include_list} ${rootmnt}/live/persistent/${persistence_list}.${device_name}
                fi
 
-               while read source dest options # < ${include_list}
+               while read dir options # < ${include_list}
                do
-                       if echo ${source} | grep -qe "^[[:space:]]*\(#.*\)\?$"
+                       if echo ${dir} | grep -qe "^[[:space:]]*\(#.*\)\?$"
                        then
                                # skipping empty or commented lines
                                continue
                        fi
 
-                       if echo ${dest} | grep -qe "^[^/]"
-                       then
-                               options="${dest}"
-                               dest="${source}"
-                       elif [ -z "${dest}" ]
-                       then
-                               dest="${source}"
-                       fi
-
-                       if trim_path ${source} | grep -qe "^\(.*/\)\?\.\.\?\(/.*\)\?$"
-                       then
-                               log_warning_msg "Skipping unsafe custom mount with source ${source}: the source is a relative or absolute path w.r.t. the persistent media root and cannot use \".\" or \"..\""
-                               continue
-                       fi
-
-                       if trim_path ${dest} | grep -q -e "^/$" -e "^/live\(/.*\)\?$" -e "^/\(.*/\)\?\.\.\?\(/.*\)\?$"
+                       if trim_path ${dir} | grep -q -e "^[^/]" -e "^/$" -e "^/live\(/.*\)\?$" -e "^/\(.*/\)\?\.\.\?\(/.*\)\?$"
                        then
-                               log_warning_msg "Skipping unsafe custom mount with desination ${dest}: the destination must be an absolute path using neither \".\" nor \"..\", and cannot be /live (or any sub-directory therein) or / (for the latter, use ${root_overlay_label}-type persistence instead)"
+                               log_warning_msg "Skipping unsafe custom mount ${dir}: must be an absolute path containing neither the \".\" nor \"..\" special dirs, and cannot be \"/live\" (or any sub-directory therein) or \"/\" (for the latter, use ${root_overlay_label}-type persistence)"
                                continue
                        fi
 
+                       local opt_source=""
+                       local opt_linkfiles=""
                        for opt in $(echo ${options} | tr ',' ' ');
                        do
                                case "${opt}" in
-                                       linkfiles|union)
+                                       source=*)
+                                               opt_source=${opt#source=}
+                                               ;;
+                                       linkfiles)
+                                               opt_linkfiles="yes"
+                                               ;;
+                                       union)
                                                ;;
                                        *)
                                                log_warning_msg "Skipping custom mount with unkown option: ${opt}"
@@ -1305,48 +1312,68 @@ get_custom_mounts ()
                                esac
                        done
 
-                       # ensure that no multiple-/ occur in paths
+                       local source="${dir}"
+                       if [ -n "${opt_source}" ]
+                       then
+                               if echo ${opt_source} | grep -q -e "^/" -e "^\(.*/\)\?\.\.\?\(/.*\)\?$" && [ "${source}" != "." ]
+                               then
+                                       log_warning_msg "Skipping unsafe custom mount with option source=${opt_source}: must be either \".\" (the media root) or a relative path w.r.t. the media root that contains neither comas, nor the special \".\" and \"..\" path components"
+                                       continue
+                               else
+                                       source="${opt_source}"
+                               fi
+                       fi
+
                        local full_source="$(trim_path ${backing}/${source})"
-                       local full_dest="$(trim_path ${rootmnt}/${dest})"
-                       device_used="yes"
-                       if echo ${options} | grep -qe "\<linkfiles\>";
+                       local full_dest="$(trim_path ${rootmnt}/${dir})"
+                       if [ -n "${opt_linkfiles}" ]
                        then
-                               echo "${full_source} ${full_dest} ${options}" >> ${links}
+                               echo "${device} ${full_source} ${full_dest} ${options}" >> ${links}
                        else
-                               echo "${full_source} ${full_dest} ${options}" >> ${bindings}
+                               echo "${device} ${full_source} ${full_dest} ${options}" >> ${bindings}
                        fi
                done < ${include_list}
-
-               if [ -z "${device_used}" ]
-               then
-                       # this device was not used for / earlier, or
-                       # custom mount point now, so it's useless
-                       umount "${backing}"
-                       rmdir "${backing}"
-               fi
        done
 
        # We sort the list according to destination so we're sure that
        # we won't hide a previous mount. We also ignore duplicate
        # destinations in a more or less arbitrary way.
-       [ -e "${bindings}" ] && sort -k2 -sbu ${bindings} >> ${custom_mounts} && rm ${bindings}
+       [ -e "${bindings}" ] && sort -k3 -sbu ${bindings} >> ${custom_mounts} && rm ${bindings}
 
        # After all mounts are considered we add symlinks so they
        # won't be hidden by some mount.
-       [ -e "${links}" ] && sort -k2 -sbu ${links} >> ${custom_mounts} && rm ${links}
+       [ -e "${links}" ] && cat ${links} >> ${custom_mounts} && rm ${links}
+
+       # We need to make sure that no two custom mounts have the same sources
+       # or are nested; if that is the case, too much weird stuff can happen.
+       local prev_source="impossible source" # first iteration must not match
+       local prev_dest=""
+       # This sort will ensure that a source /a comes right before a source
+       # /a/b so we only need to look at the previous source
+       sort -k2 -b ${custom_mounts} |
+       while read device source dest options
+       do
+               if echo ${source} | grep -qe "^${prev_source}\(/.*\)\?$"
+               then
+                       panic "Two persistent mounts have the same or nested sources: ${source} on ${dest}, and ${prev_source} on ${prev_dest}"
+               fi
+               prev_source=${source}
+               prev_dest=${dest}
+       done
 }
 
-do_custom_mounts ()
+activate_custom_mounts ()
 {
        local custom_mounts="${1}" # the ouput from get_custom_mounts()
+       local used_devices=""
 
-       while read source dest options # < ${custom_mounts}
+       while read device source dest options # < ${custom_mounts}
        do
                local opt_linkfiles=""
                local opt_union=""
                for opt in $(echo ${options} | tr ',' ' ');
                do
-                        case "${opt}" in
+                       case "${opt}" in
                                linkfiles)
                                        opt_linkfiles="yes"
                                        ;;
@@ -1356,9 +1383,14 @@ do_custom_mounts ()
                        esac
                done
 
+               if [ -n "${opt_linkfiles}" ] && [ -n "${opt_union}" ]
+               then
+                       log_warning_msg "Skipping custom mount ${dest} with options ${options}: \"linkfiles\" and \"union\" are mutually exclusive options"
+               fi
+
                if [ -n "$(what_is_mounted_on "${dest}")" ]
                then
-                       log_warning_msg "Skipping custom mount ${source} on ${dest}: $(what_is_mounted_on "${dest}") is already mounted there"
+                       log_warning_msg "Skipping custom mount ${dest}: $(what_is_mounted_on "${dest}") is already mounted there"
                        continue
                fi
 
@@ -1397,13 +1429,16 @@ do_custom_mounts ()
                # dealing with /etc or other system dir.
                if [ ! -d "${source}" ]
                then
-                       if [ -n "${PERSISTENT_READONLY}" ] || [ -n "${opt_linkfiles}" ]
+                       if [ -n "${PERSISTENT_READONLY}" ]
                        then
                                continue
-                       elif [ -n "${opt_union}" ]
+                       elif [ -n "${opt_union}" ] || [ -n "${opt_linkfiles}" ]
                        then
-                               # union's don't need to be bootstrapped
-                               mkdir "${source}"
+                               # unions and don't need to be bootstrapped
+                               # linkfiles dirs can't be bootstrapped in a sensible way
+                               mkdir -p "${source}"
+                               chown --reference "${dest}" "${source}"
+                               chmod --reference "${dest}" "${source}"
                        else
                                # ensure that $dest is not copied *into* $source
                                mkdir -p "$(dirname ${source})"
@@ -1411,6 +1446,8 @@ do_custom_mounts ()
                        fi
                fi
 
+               # XXX: If CONFIG_AUFS_ROBR is added to the Debian kernel we can
+               # ignore the loop below and set rofs_dest_backing=$dest
                rofs_dest_backing=""
                for d in ${rootmnt}/live/rofs/*
                do
@@ -1453,7 +1490,16 @@ do_custom_mounts ()
                        else
                                cow_dir="/live/cow/${dest}"
                        fi
+                       if [ -e "${cow_dir}" ]
+                       then
+                               # If an earlier custom mount has files here
+                               # it will "block" the current mount's files
+                               # which is undesirable
+                               rm -rf "${cow_dir}"
+                       fi
                        mkdir -p ${cow_dir}
+                       chown --reference "${source}" "${cow_dir}"
+                       chmod --reference "${source}" "${cow_dir}"
                        do_union ${dest} ${cow_dir} ${source} ${rofs_dest_backing}
                fi
 
@@ -1464,7 +1510,14 @@ do_custom_mounts ()
 
                PERSISTENCE_IS_ON="1"
                export PERSISTENCE_IS_ON
+
+               if echo ${used_devices} | grep -qve "^\(.* \)\?${device}\( .*\)\?$"
+               then
+                       used_devices="${used_devices} ${device}"
+               fi
        done < ${custom_mounts}
+
+       echo ${used_devices}
 }
 
 fix_home_rw_compatibility ()
@@ -1486,6 +1539,6 @@ fix_home_rw_compatibility ()
        if [ ! -r "${include_list}" ]
        then
                echo "# home-rw backwards compatibility:
-/ /home" > "${include_list}"
+/home source=." > "${include_list}"
        fi
 }